Wound Healing Apparatus For Promoting Granulation And Epithelialisation At A Tissue Site

Abstract

An apparatus for promoting granulation and epithelialisation at a tissue site having a substantially gas impermeable, flexible mat. A plurality of projections extend from a surface of the substantially gas impermeable, flexible mat, and each projection has a first end connected to the surface and a second end opposing the first end. A flexible membrane is positioned adjacent the second end of at least a portion of the plurality of projections and the flexible membrane is sufficiently flexible to allow deformation of the flexible membrane by the at least the portion of the plurality of projections when a biasing force exerted on the substantially gas impermeable, flexible mat or the plurality of projections is greater than or equal to a threshold force.

1 - 21 . (canceled) 
     
     
         22 . An apparatus for promoting wound healing, the apparatus comprising:
 a porous pad having a first compressibility; and   a plurality of granulation promoters embedded within the porous pad having a second compressibility less than the first compressibility of the porous pad, the plurality of granulation promoters positioned near a surface of the porous pad such that in the presence of a biasing force applied to the porous pad or plurality of granulation promoters that is greater than or equal to a threshold amount, the plurality of granulation promoters are configured to extend from the porous pad or alter the surface of the porous pad to promote granulation.   
     
     
         23 . The apparatus of  claim 22 , further comprising a flexible membrane adjacent the surface of the porous pad, the flexible membrane having a plurality of microperforations. 
     
     
         24 . The apparatus of  claim 22 , wherein the plurality of granulation promoters are configured not to extend from the porous pad or alter the surface of the porous pad when the biasing force is less than the threshold amount. 
     
     
         25 . The apparatus of  claim 22 , wherein at least a portion of the porous pad includes a hydrogel-forming material to promote epithelialisation. 
     
     
         26 . The apparatus of  claim 22 , wherein the plurality of granulation promoters are hollow. 
     
     
         27 . The apparatus of  claim 22 , wherein the plurality of granulation promoters are bioabsorbable. 
     
     
         28 . The apparatus of  claim 22 , wherein the plurality of granulation promoters are comprised of a hydrogel-forming material. 
     
     
         29 . An apparatus for promoting granulation and epithelialisation of a tissue site, the apparatus comprising:
 a porou foam having a tissue-contacting surface that is sufficiently rough to promote granulation; and   a hydrogel-forming material disposed in at least a portion of the porous foam, the hydrogel-forming material configured to alter the tissue-contacting surface to be sufficiently smooth to promote epithelialisation if liquid is introduced into the porous foam.   
     
     
         30 . The apparatus of  claim 29 , wherein the altered tissue-contacting surface presents a moist, smooth surface to the tissue site. 
     
     
         31 . The apparatus of  claim 29 , wherein the tissue-contacting surface has a base surface and one or more side surfaces, and wherein the hydrogel-forming material is configured to expand to alter the base surface and the one or more side surfaces to be sufficiently smooth to promote epithelialisation. 
     
     
         32 . The apparatus of  claim 29 , wherein the hydrogel-forming material is configured to release moisture in the presence of a reduced pressure greater than a threshold amount. 
     
     
         33 . The apparatus of  claim 29 , wherein the hydrogel-forming material is configured to absorb liquid and cause the hydrogel-forming material to expand when a reduced pressure is less than a threshold amount. 
     
     
         34 . A reduced pressure treatment system for administering reduced pressure treatment to a tissue site, the reduced pressure treatment system comprising:
 a reduced pressure source; and   a manifold in fluid communication with the reduced pressure source to provide a reduced pressure to the tissue site, the manifold comprising a tissue-contacting surface having a granulation configuration and an epithelialisation configuration, at least one of the granulation configuration and the epithelialisation configuration being activated by an activation stimulus.   
     
     
         35 . The reduced pressure treatment system of  claim 34 , wherein the activation stimulus is a biasing force. 
     
     
         36 . The reduced pressure treatment system of  claim 35 , wherein the manifold further comprises:
 a porous pad having a first compressibility; and   a plurality of granulation promoters embedded within the porous pad having a second compressibility less than the first compressibility of the porous pad, the plurality of granulation promoters positioned near a surface of the porous pad such that in the presence of a biasing force applied to the porous pad or plurality of granulation promoters that is greater than or equal to a threshold amount, the plurality of granulation promoters are configured to extend from the porous pad or alter the surface of the porous pad to promote granulation.   
     
     
         37 . The reduced pressure treatment system of  claim 34 , wherein the activation stimulus is a liquid introduced into the manifold. 
     
     
         38 . The reduced pressure treatment system of  claim 37 , wherein the manifold further comprises: a reticulated foam with the tissue-contacting surface being sufficiently rough to promote granulation; and
 a hydrogel-forming material disposed in at least a portion of the reticulated foam, the hydrogel-forming material configured to moisten and expand if liquid is introduced into the reticulated foam, thereby altering the tissue-contacting surface to be sufficiently smooth to promote epithelialisation.   
     
     
         39 . The reduced pressure treatment system of  claim 34 , wherein the manifold further comprises:
 a substantially gas impermeable, flexible mat;   a plurality of projections extending from a surface of the substantially gas impermeable, flexible mat, each projection having a first end connected to the surface and a second end opposing the first end; and   a flexible membrane positioned adjacent the second end of at least a portion of the plurality of projections, the flexible membrane being sufficiently flexible to allow deformation of the flexible membrane by the at least the portion of the plurality of projections when the activation stimulus is exerted on the substantially gas impermeable, flexible mat;   wherein the flexible membrane is the tissue-contacting surface.   
     
     
         40 . The reduced pressure treatment system of  claim 34 , wherein the manifold further comprises:
 a hollow mat having an inner chamber and a plurality of recesses disposed in proximity to a first surface of the hollow mat; and   an extendable projection positioned within each recess and configured to extend from the recess when activated by the activation stimulus;   wherein the activation stimulus occurs when a first pressure within the inner chamber is greater than a second pressure in the recess.   
     
     
         41 . A reduced pressure treatment system for administering reduced pressure treatment to a tissue site, the reduced pressure treatment system comprising:
 a reduced pressure source;   an apparatus fluidly coupled to the reduced pressure source, the apparatus comprising:
 a mat that is substantially gas-impermeable and flexible, 
 a flexible membrane, and 
 a plurality of projections extending from the mat, 
   the flexible membrane being sufficiently flexible to allow deformation of the flexible membrane by at least a portion of the plurality of projections when a biasing force exerted on the mat or the plurality of projections is greater than or equal to a threshold force; and   a drape formed of substantially impermeable material configured to cover the apparatus and to substantially maintain reduced pressure at the tissue site.   
     
     
         42 . The reduced pressure treatment system of  claim 41  further comprising:
 a manifold fluidly coupled to the reduced pressure source for receiving the reduced pressure and positioned between the apparatus and the drape to distribute the reduced pressure to the apparatus. 
 
     
     
         43 . The reduced pressure treatment system of  claim 41 , wherein reduced pressure from the reduced pressure source creates the biasing force. 
     
     
         44 . A reduced pressure treatment system for administering reduced pressure treatment to a tissue site, the reduced pressure treatment system comprising:
 a reduced pressure source;   an apparatus fluidly coupled to the reduced pressure source, the apparatus comprising:
 a hollow mat having an inner chamber and a plurality of recesses disposed in proximity to a first surface of the hollow mat, and 
 an extendable projection positioned within each recess and configured to extend from the recess when a first pressure within the inner chamber is greater than a second pressure in the recess; and 
   a drape formed of substantially impermeable material configured to cover the apparatus and the tissue site to substantially maintain reduced pressure at the tissue site.   
     
     
         45 . A reduced pressure treatment system for administering reduced pressure treatment to a tissue site, the reduced pressure treatment system comprising:
 a reduced pressure source;   an apparatus fluidly coupled to the reduced pressure source, the apparatus comprising:
 a porous pad having a first compressibility, and 
 a plurality of granulation promoters embedded within the porous pad having a second compressibility less than the first compressibility of the porous pad, the plurality of granulation promoters positioned near a surface of the porous pad such that in the presence of a biasing force applied to the porous pad or plurality of granulation promoters that is greater than or equal to a threshold amount, the plurality of granulation promoters extend from the porous pad or alter the surface of the porous pad to promote granulation; and 
   a drape formed of substantially impermeable material to cover the apparatus and the tissue site to substantially maintain reduced pressure at the tissue site.   
     
     
         46 . A reduced pressure treatment system for administering reduced pressure treatment to a tissue site, the reduced pressure treatment system comprising:
 a reduced pressure source;   an apparatus fluidly coupled to the reduced pressure source, the apparatus comprising:
 a porous, reticulated foam having a tissue-contacting surface that is sufficiently rough to promote granulation, and 
 a hydrogel-forming material disposed in at least a portion of the porous, reticulated foam such that introduction of a liquid into the porous, reticulated foam causes the hydrogel-forming material to moisten and expand, thereby altering the tissue-contacting surface to be sufficiently smooth to promote epithelialisation; and 
   a drape formed of substantially impermeable material to cover the apparatus and the tissue site to substantially maintain reduced pressure at the tissue site.   
     
     
         47 . A method for selectively promoting granulation and epithelialisation of a tissue site, the method comprising:
 positioning a pad having a tissue-contacting surface at the tissue site;   applying a first reduced pressure to the tissue site when the tissue-contacting surface is in a first configuration to promote granulation;   changing the first configuration of the tissue-contacting surface to a second configuration; and   applying a second reduced pressure to the tissue site when the tissue-contacting surface is in the second configuration to promote epithelialisation.   
     
     
         48 . The method of  claim 47 , wherein the first configuration includes a substantially rough tissue-contacting surface to promote granulation. 
     
     
         49 . The method of  claim 47 , wherein the second configuration includes a substantially smooth tissue-contacting surface to promote epithelialisation. 
     
     
         50 . The method of  claim 47 , wherein changing the first configuration to the second configuration comprises removing a biasing force applied to the pad. 
     
     
         51 . The method of  claim 47 , wherein changing the first configuration to the second configuration comprises introducing a liquid to the pad. 
     
     
         52 . The method of  claim 51 , wherein introducing the liquid further comprises absorbing exudate into the pad from the tissue site. 
     
     
         53 . The method of  claim 51 , wherein introducing the liquid further comprises introducing saline into the pad. 
     
     
         54 . A treatment device for positioning in contact with a tissue site to be treated, the device having a tissue-facing surface with a roughness which is variable dependent on a physical input. 
     
     
         55 . A treatment device according to  claim 54 , wherein the device comprises
 a flexible mat with a plurality of projections extending from a surface of the mat towards the tissue-facing surface, and   a flexible membrane for contact with the tissue site and covering the ends of the projections distal from the mat.   
     
     
         56 . A treatment device according to  claim 55 , wherein the flexible membrane distorts towards the flexible mat between the projections to increase the roughness of the tissue-facing surface. 
     
     
         57 . A treatment device according to  claim 55 , wherein the mat is substantially fluid impermeable. 
     
     
         58 . A treatment device according to  claim 55 , wherein the membrane comprises a plurality of microperforations configured to expand as the membrane distorts. 
     
     
         59 . A treatment device according to  claim 58 , wherein the microperforations coincide with the projections, such that the projections extend through the microperforations to increase the surface roughness. 
     
     
         60 . A treatment device according to  claim 55 , further comprising:
 a drape for sealing around the tissue site to create an enclosed space, and   a reduced-pressure source for creating a reduced pressure in the enclosed space, wherein the reduced-pressure is the physical input.   
     
     
         61 . A treatment device according to  claim 54  comprising a hollow mat having a sealed inner chamber with a chamber wall, the chamber wall having a plurality of retractable projections on the tissue-facing surface of the device. 
     
     
         62 . A treatment device according to  claim 54  comprising a hollow mat having an inner chamber with a vent pipe configured for providing a fluid connection to a remote location, the chamber wall having a plurality of retractable projections on the tissue-facing surface of the device. 
     
     
         63 . A treatment device according to  claim 61 , wherein the projections are movable between a retracted position and an extended position dependent on a pressure differential between the inner chamber and outside the inner chamber. 
     
     
         64 . A treatment device according to  claim 61 , wherein the projections retract into recesses in the chamber wall. 
     
     
         65 . A treatment device according to  claims 61 , wherein the projections are telescopic to permit movement between the retracted and extended positions. 
     
     
         66 . A treatment device according to  claims 61 , wherein the projections comprise bellows to permit movement between the retracted and extended positions. 
     
     
         67 . A treatment device according to  claim 61 , comprising a pump for varying pressure within the inner chamber. 
     
     
         68 . A treatment device according to  claim 61 , further comprising a flexible membrane covering the tissue-facing surface of the device. 
     
     
         69 . A treatment device according to  claim 68 , wherein the membrane comprises openings aligned with the projections.